What caused the paint and sheet metal of the left rear door?

1. A car collided, causing damage to the left rear door and surrounding body parts.

2. When the vehicle is parked or driving, it will contact with other objects or vehicles, resulting in scratches or scratches, which will damage the coating on the surface of the left rear door.

3. Long-term exposure to bad weather conditions, such as acid rain, sunlight, pollutants in the air, etc., will gradually oxidize and fade the paint surface of the left back door.